A Silicon Photomultiplier (SiPM) is a photon sensitive, high performance, solid-state sensor. It is formed of a summed array of closely-packed Single Photon Avalanche Photodiode (SPAD) sensors with integrated quench resistors, resulting in a compact sensor that has high gain (˜1×106), high detection efficiency (>50%) and fast timing (sub-ns rise times) all achieved at a bias voltage of ˜30V.
Traditionally LiDAR with analogue SiPMs is performed by discriminating the output of the SiPM against a fixed threshold corresponding to N-photons, where N is typical set to 1 to allow single-photon detection. However, in high light conditions, many close-in-time photons contribute to the output current/voltage with increments beyond the fixed single-photon threshold. Such contributions are therefore lost by the discriminator liming the number of timestamps of the readout. Increasing the threshold however results in the loss of the information of the single-photon events, which is important for the fast detection high and low light levels
There is therefore a need to provide for a LiDAR readout circuit which addresses at least some of the drawbacks of the prior art.